Two For One(TFO) Filament Spindles RPM Suitable Bolster 50mm, 60mm, 70mm, 80mm. 8000-15000 HF 21/HF1 90mm, 110mm. 8000-12000 HF 21/HF2C All Size of Two For One twisting spindles are available such as 50 mm, 60 mm, 70 mm, 90 mm and 140 mm. Two types of coatings are available in Aluminium Pot.